#include "blk.h"
+struct bio_map_data {
+ int is_our_pages;
+ struct iov_iter iter;
+ struct iovec iov[];
+};
+
+static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
+ gfp_t gfp_mask)
+{
+ struct bio_map_data *bmd;
+
+ if (data->nr_segs > UIO_MAXIOV)
+ return NULL;
+
+ bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask);
+ if (!bmd)
+ return NULL;
+ memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
+ bmd->iter = *data;
+ bmd->iter.iov = bmd->iov;
+ return bmd;
+}
+
+/**
+ * bio_copy_from_iter - copy all pages from iov_iter to bio
+ * @bio: The &struct bio which describes the I/O as destination
+ * @iter: iov_iter as source
+ *
+ * Copy all pages from iov_iter to bio.
+ * Returns 0 on success, or error on failure.
+ */
+static int bio_copy_from_iter(struct bio *bio, struct iov_iter *iter)
+{
+ struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
+
+ bio_for_each_segment_all(bvec, bio, iter_all) {
+ ssize_t ret;
+
+ ret = copy_page_from_iter(bvec->bv_page,
+ bvec->bv_offset,
+ bvec->bv_len,
+ iter);
+
+ if (!iov_iter_count(iter))
+ break;
+
+ if (ret < bvec->bv_len)
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+/**
+ * bio_copy_to_iter - copy all pages from bio to iov_iter
+ * @bio: The &struct bio which describes the I/O as source
+ * @iter: iov_iter as destination
+ *
+ * Copy all pages from bio to iov_iter.
+ * Returns 0 on success, or error on failure.
+ */
+static int bio_copy_to_iter(struct bio *bio, struct iov_iter iter)
+{
+ struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
+
+ bio_for_each_segment_all(bvec, bio, iter_all) {
+ ssize_t ret;
+
+ ret = copy_page_to_iter(bvec->bv_page,
+ bvec->bv_offset,
+ bvec->bv_len,
+ &iter);
+
+ if (!iov_iter_count(&iter))
+ break;
+
+ if (ret < bvec->bv_len)
+ return -EFAULT;
+ }
+
+ return 0;
+}
+
+/**
+ * bio_uncopy_user - finish previously mapped bio
+ * @bio: bio being terminated
+ *
+ * Free pages allocated from bio_copy_user_iov() and write back data
+ * to user space in case of a read.
+ */
+static int bio_uncopy_user(struct bio *bio)
+{
+ struct bio_map_data *bmd = bio->bi_private;
+ int ret = 0;
+
+ if (!bio_flagged(bio, BIO_NULL_MAPPED)) {
+ /*
+ * if we're in a workqueue, the request is orphaned, so
+ * don't copy into a random user address space, just free
+ * and return -EINTR so user space doesn't expect any data.
+ */
+ if (!current->mm)
+ ret = -EINTR;
+ else if (bio_data_dir(bio) == READ)
+ ret = bio_copy_to_iter(bio, bmd->iter);
+ if (bmd->is_our_pages)
+ bio_free_pages(bio);
+ }
+ kfree(bmd);
+ bio_put(bio);
+ return ret;
+}
+
+/**
+ * bio_copy_user_iov - copy user data to bio
+ * @q: destination block queue
+ * @map_data: pointer to the rq_map_data holding pages (if necessary)
+ * @iter: iovec iterator
+ * @gfp_mask: memory allocation flags
+ *
+ * Prepares and returns a bio for indirect user io, bouncing data
+ * to/from kernel pages as necessary. Must be paired with
+ * call bio_uncopy_user() on io completion.
+ */
+static struct bio *bio_copy_user_iov(struct request_queue *q,
+ struct rq_map_data *map_data, struct iov_iter *iter,
+ gfp_t gfp_mask)
+{
+ struct bio_map_data *bmd;
+ struct page *page;
+ struct bio *bio;
+ int i = 0, ret;
+ int nr_pages;
+ unsigned int len = iter->count;
+ unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0;
+
+ bmd = bio_alloc_map_data(iter, gfp_mask);
+ if (!bmd)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * We need to do a deep copy of the iov_iter including the iovecs.
+ * The caller provided iov might point to an on-stack or otherwise
+ * shortlived one.
+ */
+ bmd->is_our_pages = map_data ? 0 : 1;
+
+ nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
+ if (nr_pages > BIO_MAX_PAGES)
+ nr_pages = BIO_MAX_PAGES;
+
+ ret = -ENOMEM;
+ bio = bio_kmalloc(gfp_mask, nr_pages);
+ if (!bio)
+ goto out_bmd;
+
+ ret = 0;
+
+ if (map_data) {
+ nr_pages = 1 << map_data->page_order;
+ i = map_data->offset / PAGE_SIZE;
+ }
+ while (len) {
+ unsigned int bytes = PAGE_SIZE;
+
+ bytes -= offset;
+
+ if (bytes > len)
+ bytes = len;
+
+ if (map_data) {
+ if (i == map_data->nr_entries * nr_pages) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ page = map_data->pages[i / nr_pages];
+ page += (i % nr_pages);
+
+ i++;
+ } else {
+ page = alloc_page(q->bounce_gfp | gfp_mask);
+ if (!page) {
+ ret = -ENOMEM;
+ break;
+ }
+ }
+
+ if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes) {
+ if (!map_data)
+ __free_page(page);
+ break;
+ }
+
+ len -= bytes;
+ offset = 0;
+ }
+
+ if (ret)
+ goto cleanup;
+
+ if (map_data)
+ map_data->offset += bio->bi_iter.bi_size;
+
+ /*
+ * success
+ */
+ if ((iov_iter_rw(iter) == WRITE &&
+ (!map_data || !map_data->null_mapped)) ||
+ (map_data && map_data->from_user)) {
+ ret = bio_copy_from_iter(bio, iter);
+ if (ret)
+ goto cleanup;
+ } else {
+ if (bmd->is_our_pages)
+ zero_fill_bio(bio);
+ iov_iter_advance(iter, bio->bi_iter.bi_size);
+ }
+
+ bio->bi_private = bmd;
+ if (map_data && map_data->null_mapped)
+ bio_set_flag(bio, BIO_NULL_MAPPED);
+ return bio;
+cleanup:
+ if (!map_data)
+ bio_free_pages(bio);
+ bio_put(bio);
+out_bmd:
+ kfree(bmd);
+ return ERR_PTR(ret);
+}
+
+/**
+ * bio_map_user_iov - map user iovec into bio
+ * @q: the struct request_queue for the bio
+ * @iter: iovec iterator
+ * @gfp_mask: memory allocation flags
+ *
+ * Map the user space address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+static struct bio *bio_map_user_iov(struct request_queue *q,
+ struct iov_iter *iter, gfp_t gfp_mask)
+{
+ int j;
+ struct bio *bio;
+ int ret;
+
+ if (!iov_iter_count(iter))
+ return ERR_PTR(-EINVAL);
+
+ bio = bio_kmalloc(gfp_mask, iov_iter_npages(iter, BIO_MAX_PAGES));
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ while (iov_iter_count(iter)) {
+ struct page **pages;
+ ssize_t bytes;
+ size_t offs, added = 0;
+ int npages;
+
+ bytes = iov_iter_get_pages_alloc(iter, &pages, LONG_MAX, &offs);
+ if (unlikely(bytes <= 0)) {
+ ret = bytes ? bytes : -EFAULT;
+ goto out_unmap;
+ }
+
+ npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE);
+
+ if (unlikely(offs & queue_dma_alignment(q))) {
+ ret = -EINVAL;
+ j = 0;
+ } else {
+ for (j = 0; j < npages; j++) {
+ struct page *page = pages[j];
+ unsigned int n = PAGE_SIZE - offs;
+ bool same_page = false;
+
+ if (n > bytes)
+ n = bytes;
+
+ if (!__bio_add_pc_page(q, bio, page, n, offs,
+ &same_page)) {
+ if (same_page)
+ put_page(page);
+ break;
+ }
+
+ added += n;
+ bytes -= n;
+ offs = 0;
+ }
+ iov_iter_advance(iter, added);
+ }
+ /*
+ * release the pages we didn't map into the bio, if any
+ */
+ while (j < npages)
+ put_page(pages[j++]);
+ kvfree(pages);
+ /* couldn't stuff something into bio? */
+ if (bytes)
+ break;
+ }
+
+ bio_set_flag(bio, BIO_USER_MAPPED);
+
+ /*
+ * subtle -- if bio_map_user_iov() ended up bouncing a bio,
+ * it would normally disappear when its bi_end_io is run.
+ * however, we need it for the unmap, so grab an extra
+ * reference to it
+ */
+ bio_get(bio);
+ return bio;
+
+ out_unmap:
+ bio_release_pages(bio, false);
+ bio_put(bio);
+ return ERR_PTR(ret);
+}
+
+/**
+ * bio_unmap_user - unmap a bio
+ * @bio: the bio being unmapped
+ *
+ * Unmap a bio previously mapped by bio_map_user_iov(). Must be called from
+ * process context.
+ *
+ * bio_unmap_user() may sleep.
+ */
+static void bio_unmap_user(struct bio *bio)
+{
+ bio_release_pages(bio, bio_data_dir(bio) == READ);
+ bio_put(bio);
+ bio_put(bio);
+}
+
+static void bio_invalidate_vmalloc_pages(struct bio *bio)
+{
+#ifdef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
+ if (bio->bi_private && !op_is_write(bio_op(bio))) {
+ unsigned long i, len = 0;
+
+ for (i = 0; i < bio->bi_vcnt; i++)
+ len += bio->bi_io_vec[i].bv_len;
+ invalidate_kernel_vmap_range(bio->bi_private, len);
+ }
+#endif
+}
+
+static void bio_map_kern_endio(struct bio *bio)
+{
+ bio_invalidate_vmalloc_pages(bio);
+ bio_put(bio);
+}
+
+/**
+ * bio_map_kern - map kernel address into bio
+ * @q: the struct request_queue for the bio
+ * @data: pointer to buffer to map
+ * @len: length in bytes
+ * @gfp_mask: allocation flags for bio allocation
+ *
+ * Map the kernel address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+static struct bio *bio_map_kern(struct request_queue *q, void *data,
+ unsigned int len, gfp_t gfp_mask)
+{
+ unsigned long kaddr = (unsigned long)data;
+ unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = kaddr >> PAGE_SHIFT;
+ const int nr_pages = end - start;
+ bool is_vmalloc = is_vmalloc_addr(data);
+ struct page *page;
+ int offset, i;
+ struct bio *bio;
+
+ bio = bio_kmalloc(gfp_mask, nr_pages);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ if (is_vmalloc) {
+ flush_kernel_vmap_range(data, len);
+ bio->bi_private = data;
+ }
+
+ offset = offset_in_page(kaddr);
+ for (i = 0; i < nr_pages; i++) {
+ unsigned int bytes = PAGE_SIZE - offset;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ if (!is_vmalloc)
+ page = virt_to_page(data);
+ else
+ page = vmalloc_to_page(data);
+ if (bio_add_pc_page(q, bio, page, bytes,
+ offset) < bytes) {
+ /* we don't support partial mappings */
+ bio_put(bio);
+ return ERR_PTR(-EINVAL);
+ }
+
+ data += bytes;
+ len -= bytes;
+ offset = 0;
+ }
+
+ bio->bi_end_io = bio_map_kern_endio;
+ return bio;
+}
+
+static void bio_copy_kern_endio(struct bio *bio)
+{
+ bio_free_pages(bio);
+ bio_put(bio);
+}
+
+static void bio_copy_kern_endio_read(struct bio *bio)
+{
+ char *p = bio->bi_private;
+ struct bio_vec *bvec;
+ struct bvec_iter_all iter_all;
+
+ bio_for_each_segment_all(bvec, bio, iter_all) {
+ memcpy(p, page_address(bvec->bv_page), bvec->bv_len);
+ p += bvec->bv_len;
+ }
+
+ bio_copy_kern_endio(bio);
+}
+
+/**
+ * bio_copy_kern - copy kernel address into bio
+ * @q: the struct request_queue for the bio
+ * @data: pointer to buffer to copy
+ * @len: length in bytes
+ * @gfp_mask: allocation flags for bio and page allocation
+ * @reading: data direction is READ
+ *
+ * copy the kernel address into a bio suitable for io to a block
+ * device. Returns an error pointer in case of error.
+ */
+static struct bio *bio_copy_kern(struct request_queue *q, void *data,
+ unsigned int len, gfp_t gfp_mask, int reading)
+{
+ unsigned long kaddr = (unsigned long)data;
+ unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned long start = kaddr >> PAGE_SHIFT;
+ struct bio *bio;
+ void *p = data;
+ int nr_pages = 0;
+
+ /*
+ * Overflow, abort
+ */
+ if (end < start)
+ return ERR_PTR(-EINVAL);
+
+ nr_pages = end - start;
+ bio = bio_kmalloc(gfp_mask, nr_pages);
+ if (!bio)
+ return ERR_PTR(-ENOMEM);
+
+ while (len) {
+ struct page *page;
+ unsigned int bytes = PAGE_SIZE;
+
+ if (bytes > len)
+ bytes = len;
+
+ page = alloc_page(q->bounce_gfp | gfp_mask);
+ if (!page)
+ goto cleanup;
+
+ if (!reading)
+ memcpy(page_address(page), p, bytes);
+
+ if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes)
+ break;
+
+ len -= bytes;
+ p += bytes;
+ }
+
+ if (reading) {
+ bio->bi_end_io = bio_copy_kern_endio_read;
+ bio->bi_private = data;
+ } else {
+ bio->bi_end_io = bio_copy_kern_endio;
+ }
+
+ return bio;
+
+cleanup:
+ bio_free_pages(bio);
+ bio_put(bio);
+ return ERR_PTR(-ENOMEM);
+}
+
/*
* Append a bio to a passthrough request. Only works if the bio can be merged
* into the request based on the driver constraints.
projects / linux-2.6-microblaze.git / blobdiff